+dnl check for GNU Make if we have GCC and autodepend is on.
+if test "$GCC" = yes && test "$ac_enable_autodepend" = yes; then
+ AC_MSG_CHECKING([whether we are using GNU Make])
+ HAVE_GNU_MAKE=no
+ testval=`make --version 2>/dev/null | grep 'GNU Make'`
+ if test "x$testval" != x; then
+ HAVE_GNU_MAKE=yes
+ else
+ ac_enable_autodepend=no
+ fi
+ AC_MSG_RESULT([$HAVE_GNU_MAKE])
+ if test $HAVE_GNU_MAKE = yes; then
+ AC_MSG_CHECKING([whether gcc understands -MMD -MF])
+ SAVE_CFLAGS="$CFLAGS"
+ CFLAGS="$CFLAGS -MMD -MF deps.d"
+ AC_TRY_COMPILE([], [], , ac_enable_autodepend=no)
+ CFLAGS="$SAVE_CFLAGS"
+ test -f deps.d || ac_enable_autodepend=no
+ rm -rf deps.d
+ AC_MSG_RESULT([$ac_enable_autodepend])
+ fi
+ if test $ac_enable_autodepend = yes; then
+ AC_DEFINE(AUTO_DEPEND, 1, [Generate dependencies with gcc.])
+ fi
+fi
+